Novell LINUX ENTERPRISE SERVER 11 - ADMINISTRATION Administration Manual page 193

monitoring changes (akpi, acpiw, gtkacpiw) and tools for editing the ACPI tables in
the BIOS (package pmtools).
15.2.3 Troubleshooting
There are two different types of problems. On one hand, the ACPI code of the kernel
may contain bugs that were not detected in time. In this case, a solution will be made
available for download. More often, the problems are caused by the BIOS. Sometimes,
deviations from the ACPI specification are purposely integrated in the BIOS to circum-
vent errors in the ACPI implementation of other widespread operating systems. Hardware
components that have serious errors in the ACPI implementation are recorded in a
blacklist that prevents the Linux kernel from using ACPI for these components.
The first thing to do when problems are encountered is to update the BIOS. If the
computer does not boot at all, one of the following boot parameters may be helpful:
pci=noacpi
Do not use ACPI for configuring the PCI devices.
acpi=ht
Only perform a simple resource configuration. Do not use ACPI for other purposes.
acpi=off
Disable ACPI.
WARNING: Problems Booting without ACPI
Some newer machines (especially SMP systems and AMD64 systems) need ACPI
for configuring the hardware correctly. On these machines, disabling ACPI can
cause problems.
Sometimes, the machine is confused by hardware that is attached over USB or FireWire.
If a machine refuses to boot, unplug all unneeded hardware and try again.
Monitor the boot messages of the system with the command dmesg | grep -2i
acpi (or all messages, because the problem may not be caused by ACPI) after booting.
If an error occurs while parsing an ACPI table, the most important table—the DS-
DT—can be replaced with an improved version. In this case, the faulty DSDT of the
Power Management 179